Not enough!!!
I've always been a good sleeper, needing between 7-9hrs on average. But in the last year or more I have only managed this once or twice. My average is 4-5hrs these days. I hate insomnia! The irony is that when I was younger, like TXgolfer, I hated sleep thinking it was a waste of time and for years I experimented with different ways of having less sleep - always failing and ending up with the usual 8hrs. Now that my wish has come true I find that tiredness means I do far less during the day and enjoy things less, so the extra time awake doesn't translate into getting more out of the day. I'm incapable of napping during the day either.